Backlight device

ABSTRACT

A backlight device is provided and includes case having bottom plate; light guide having front surface as emission surface, rear surface opposed to front surface, and incidence surface that is one of side surfaces of light guide, rear surface facing to bottom plate; light-emitting elements facing incident surface of light guide, each of light-emitting elements having bottom surface and light-emitting surface facing incidence surface of light guide; fixing tape arranged on bottom plate, each of bottom surfaces of light-emitting elements and rear surface of light guide being adhered to fixing tape; and light-shield facing fixing tape through light guide.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/545,560, filed on Dec. 8, 2021, which is a continuation of U.S.patent application Ser. No. 17/200,224, filed on Mar. 12, 2021, now U.S.Pat. No. 11,209,695, issued on Dec. 28, 2021, which is a continuation ofU.S. patent application Ser. No. 16/196,428, filed on Nov. 20, 2018, nowU.S. Pat. No. 10,948,768, issued on Mar. 16, 2021, which application isbased upon and claims the benefit of priority from Japanese PatentApplication No. 2017-226210, filed Nov. 24, 2017, the entire contents ofwhich are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to a backlight device anda liquid crystal display device comprising the same.

BACKGROUND

Liquid crystal display devices have been widely used as display devicesof smartphones, tablet computers, vehicle-navigation systems and thelike. In general, a liquid crystal display device comprises a liquidcrystal panel and a backlight device which illuminates the liquidcrystal panel. The backlight device comprises a frame (or bezel), areflective layer, a light guide, an optical sheet (prism sheet ordiffusing sheet), a light source device (light source unit) whichsupplies light made incident on the light guide and the like. The lightsource unit comprises a wiring board such as an FPC and a plurality oflight sources (for example, light-emitting diodes (LEDs)) mounted on thewiring board.

To narrow the frame of the liquid crystal display device, the width ofthe frame is reduced mainly along the right side and the left side.Recently, there has been increasing demand for large reduction of thewidth on the light source side (light entering side).

SUMMARY

The present application relates generally to a backlight device and aliquid crystal display device including the same.

According to one embodiment, a backlight device includes a case having abottom plate, a light guide having an emission surface, a second mainsurface and an incidence surface and arranged on the bottom surface, anda light source unit including a wiring board and light-emitting elementson the wiring board. Each light-emitting element has a mounting surface,a first side surface opposed to the mounting surface, and alight-emitting surface between the mounting surface and the first sidesurface. Each light-emitting surface faces the incidence surface, andthe first side surfaces are arranged parallel to the second mainsurface, and the light source unit is fixed to the light guide with afixing tape attached over each first side surface and the second mainsurface.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing a display surface side of a liquidcrystal display device according to an embodiment.

FIG. 2 is an exploded perspective view of the liquid crystal displaydevice.

FIG. 3 is an exploded perspective view of a backlight device of theliquid crystal display device.

FIG. 4 is a sectional view of a light source side portion of the liquidcrystal display device taken along line A-A of FIG. 1 .

FIG. 5 is a perspective view showing a light source unit of thebacklight device.

DETAILED DESCRIPTION

Various embodiments will be described hereinafter with reference to theaccompanying drawings. In general, according to one embodiment, abacklight device comprises a case having a bottom plate; a light guidehaving a first main surface as an emission surface, a second mainsurface opposed to the first main surface, and an incidence surfaceprovided between the first main surface and the second main surface, thesecond main surface being arranged on the bottom plate; and a lightsource unit configured to emit light to the incidence surface andcomprising a wiring board with a wiring line and a plurality oflight-emitting elements mounted on the wiring board. Each of thelight-emitting elements has a mounting surface mounted on the wiringboard, a first side surface opposed to the mounting surface, and alight-emitting surface provided between the mounting surface and thefirst side surface, and each of the light-emitting surfaces faces theincidence surface. Each of the first side surfaces and the second mainsurface are arranged side by side, and the light source unit is fixed tothe light guide with a fixing tape attached over each of the first sidesurfaces and the second main surface.

The disclosure is merely an example, and proper changes in keeping withthe spirit of the invention, which are easily conceivable by a personwith ordinary skill in the art, come within the scope of the inventionas a matter of course. In addition, in some cases, in order to make thedescription clearer, the widths, thicknesses, shapes, etc., of therespective parts are illustrated schematically in the drawings, ratherthan as an accurate representation of what is implemented. However, suchschematic illustration is merely exemplary, and in no way restricts theinterpretation of the invention. In addition, in the specification anddrawings, the same elements as those described in connection withpreceding drawings are denoted by like reference numbers, and detaileddescription thereof is omitted unless necessary.

(Embodiment)

FIG. 1 is a perspective view showing a display surface side of a liquidcrystal display device according to an embodiment, and FIG. 2 is anexploded perspective view of the liquid crystal display device.

A liquid crystal display device 10 can be incorporated into variouselectronic devices such as a smartphone, a tablet computer, a portabletelephone, a notebook computer, a portable game console, an electronicdictionary, a television receiver and an vehicle-navigation system.

As shown in FIGS. 1 and 2 , the liquid crystal display device 10comprises an active-matrix liquid crystal display panel (liquid crystalpanel) 12, a cover panel 14 which overlaps a display surface 12 a whichis one surface of the liquid crystal panel 12 and covers the entiredisplay surface 12 a, and a backlight unit (backlight device) 20 opposedto a rear surface of the liquid crystal panel 12 which is the othersurface of the liquid crystal panel 12.

FIG. 4 is a sectional view of a light source side of the liquid crystaldisplay device taken along line A-A of FIG. 1 . As shown in FIGS. 2 and4 , the liquid crystal panel 12 comprises a first substrate SUB1 whichhas the shape of a rectangular flat plate, a second substrate SUB2 whichhas the shape of a rectangular flat plate and faces the first substrateSUB1, and a liquid crystal layer LQ sealed between the first substrateSUB1 and the second substrate SUB2. Each of the first substrate SUB1 andthe second substrate SUB2 is formed of a transparent insulatingsubstrate such as a glass plate or a resin plate. A peripheral portionof the second substrate SUB2 is attached to the first substrate SUB1with a sealing member SE. A polarizer PL2 is attached to a surface ofthe second substrate SUB2, and the display surface 12 a of the liquidcrystal panel 12 is thereby formed. A polarizer PL1 is attached to asurface of the first substrate SUB1 (rear surface of the liquid crystalpanel 12).

On the liquid crystal panel 12, a rectangular display area (active area)DA is provided inside the sealing member SE as the liquid crystal panel12 is seen in plan view (in other words, when the liquid crystal panelis seen from the normal direction of the display surface). An image isdisplayed on the display area DA. A rectangular frame area ED isprovided around the display area DA. The liquid crystal panel 12 has atransmissive display function which displays an image by selectivelytransmitting light from the backlight unit 20 to the display area DA.

In the example illustrated, a flexible printed circuit (FPC) 22 iscoupled to a short side end portion of the first substrate SUB1 andextends outward from the liquid crystal panel 12. A semiconductorelement such as a driver IC chip 21 is mounted on the FPC 22 as a signalsupply source which supplies signals necessary for driving the liquidcrystal panel 12.

As shown in FIGS. 1, 2 and 4 , the cover panel 14 is formed of, forexample, a glass plate or acrylic transparent resin and has the shape ofa rectangular plate. A frame-shaped light-shielding layer RS is formedon a peripheral portion of a rear surface of the cover panel 14 (asurface on the liquid crystal panel 12 side or a surface opposite to asurface facing the viewer). The light-shielding layer RS may be formedon an upper surface (display surface) of the cover panel 14. The rearsurface (rear surface) of the cover panel 14 is attached to thepolarizer PL2 of the liquid crystal panel 12 with an adhesive withoptical transparency.

FIG. 3 is an exploded perspective view of the backlight unit 20. Asshown in FIGS. 2, 3 and 4 , the backlight unit 20 comprises a case 23, aplurality of optical members arranged in the case 23, and a light sourceunit 30 which supplies light made incident on the optical members. Inthe present embodiment, the case 23 comprises a rectangular bottom plate17, a plurality of side plates which stand along the side edges of thebottom plate 17, and a rectangular frame 16 which is attached firmly tothe side plates. The frame 16 and the bottom plate 17 can be integrallyformed of resin or metal. Alternatively, one of them can be formed ofresin and the other one of them can be formed of metal. In the presentembodiment, the bottom plate 17 and the side plates are formed of metalsuch as stainless steel (SUS), and the frame 16 is formed of resin. Theframe 16 is integrally formed with the side plates by insert molding orthe like. The frame 16 and the side plates constitute a pair of longside plates 16 a and 16 b which face each other and a pair of short sideplates 16 c and 16 d which face each other.

The frame 16 is formed in the shape of a frame in the presentembodiment, but the frame 16 may be provided only along the pair ofshort sides of the backlight unit. Alternatively, the frame 16 may beprovided only along one of the pair of short sides.

The optical members of the backlight unit 20 comprise a reflective sheetRE which is mounted on the bottom plate 17 inside the frame 16, a lightguide LG, a plurality of optical sheets, for example, two opticalsheets, namely, a first optical sheet OS1 and a second optical sheet OS2which are overlaid on the light guide LG.

The reflective sheet RE has the shape of a rectangle in a plan view, anddimensions thereof are slightly less than the inner dimensions of theframe 16. The reflective sheet RE is mounted on the bottom plate 17 andcovers substantially the entire surface of the bottom plate 17.

The light guide LG is formed of resin having optical transparency suchas acrylic or silicon resin in the shape of a rectangularparallelepiped. The light guide LG has a first main surface S1 which isan emission surface, a second main surface S2 which is opposite to thefirst main surface S1, and a plurality of side surfaces which cross thefirst and second main surfaces. In the present embodiment, one sidesurface along one short side of the light guide LG is assumed to be anincidence surface EF.

The light guide plate LG is arranged inside the frame 16 in a statewhere a second main surface S2 side thereof faces the reflective sheetRE, and is mounted on the reflective sheet RE. The incidence surface EFfaces the short side plate 16 d of the frame 16 across a space.

According to the present embodiment, a diffusing sheet is used as thefirst optical sheet OS1, and a prism sheet is used as the second opticalsheet OS2. The optical sheets OS1 and OS2 are overlaid in order on thefirst main surface S1 of the light guide LG The number of optical sheetsis not limited to two but may be three or more or two or less.

As shown in FIG. 4 , the first optical sheet (diffusing sheet) OS1 has alight source side end portion (short side end portion) OSE. The endportion OSE extends beyond the incidence surface EF of the light guideLG and projects from the light guide LG toward the light source. Morespecifically, the end portion OSE covers an abutting surface between theincidence surface EF and the LEDs (which will be described later) of thelight source unit. A black print BP is formed on an upper surface(surface on the liquid crystal panel 12 side) of the end portion OSE.The black print BP extends throughout the entire length of the shortside of the first optical sheet OS1. An area of the first optical sheetwhich has a black print may be assumed to be the end portion OSE.

Further, a strip-shaped light-shielding tape 45 is attached so as tooverlap the black print BP. The end portion OSE is light-shielded andlight leakage from the end portion OSE is prevented by the black printBP and the light-shielding tape 45. In the present embodiment, the widthof the light-shielding tape 45 is less than the width of the black printBP (that is, the width of the end portion OSE). Alternatively, the widthof the light-shielding tape 45 may be greater than the width of theblack print BP. Further, an end portion of the light-shielding tape 45may project outward from the first optical sheet OS1.

Next, the light source unit (light source device) 30 of the backlightunit 20 will be described in detail. FIG. 5 is a perspective view of anLED mounting side of the light source unit.

As shown in FIG. 5 , the light source unit 30 comprises a strip-shapedflexible printed circuit board (FPC) 32 which functions as a wiringboard, and a plurality of light sources which are mounted on the FPC 32.The FPC 32 has substantially the same length as that of the short sidesof the case 23 and has a pair of side edges 32 a and 32 b which extendparallel to each other. The FPC 32 has a connecting end portion 32 cwhich is integrally formed and extends from one side edge 32 b. The FPC32 comprises a plurality of connecting pads 41 and a plurality of wiringlines 40 which are formed of a conductive layer, and the connecting pads41 are exposed at one surface of the FPC 32. A width W1 of the FPC 32 isless than a distance D1 (see FIG. 4 ) between the incidence surface EFof the light guide LG and an outer surface of the short side plate 16 d.

In the present embodiment, as the light sources, a plurality oflight-emitting elements which are point light sources, for example, aplurality of light-emitting diodes (LEDs) 34 are arranged atpredetermined intervals. Each of the LEDs 34 comprises a case(enclosure) having substantially the shape of a rectangularparallelepiped. The case has a mounting surface 34 b, a first sidesurface 34 c opposed to the mounting surface 34 b, and a light-emittingsurface 34 a which emits light provided between the mounting surface 34b and the first surface 34 c. A pair of connecting terminals (not shown)are provided on the mounting surface 34 b.

Mounting surface 34 b sides of the LEDs 34 are mounted on one surface ofthe FPC 32. More specifically, the pair of connecting terminals of theLED 34 are electrically and mechanically coupled to the connecting pads41 of the FPC 32. The LED 34 is mounted on the FPC 32 such that an endportion thereof including the light-emitting surface 34 a projectsoutward from the side edge 32 a of the FPC 32. The light-emittingsurface 34 a is separated from the side edge 32 a and is substantiallyparallel to the side edge 32 a.

The LEDs 34 are arranged at predetermined intervals in a longitudinaldirection of the FPC 32 (a direction parallel to the side edges 32 a and32 b or a direction parallel to the short side plate 16 d of the frame16). The light-emitting surfaces 34 a of the LEDs 34 are substantiallyflush with one another along the side edge 32 a. The arrangement pitchof the LEDs 34 or the distance between two adjacent LEDs 34 can beappropriately determined. As described above, the width W1 of the FPC 32is reduced as much as possible, and as a result, the light-emittingsurfaces 34 a of the LEDs 34 project from the FPC 32. The width W1 ofthe FPC 32 should preferably be about 1 to 1.5 times a depth from thelight-emitting surfaces 34 a of the LEDs 34.

The light source unit 30 constituted as described above is arranged inthe case 23 and is fixed to and supported on the light guide LG with afixing tape TP2.

As shown in FIG. 4 , the light source unit 30 is arranged in the case23. That is, the LEDs 34 are arranged between the incidence surface EFof the light guide LG and the short side plate 16 d inside the case 23,and the light-emitting surfaces 34 a of the LEDs 34 face the incidencesurface EP across a small space in parallel or abut the incidencesurface EF in parallel. The FPC 32 is arranged along the short sideplate 16 d, and a side edge portion thereof on the side edge 32 b sideis mounted on the short side plate 16 d. The FPC 32 is located insubstantially the same plane as the first optical sheet OS1 and facesthe bottom plate 17 across the LEDs 34. The side edge 32 a of the FPC 32is separated from the incidence surface EF toward the short side plate16 d and faces the end portion OSE of the first optical sheet OS1 acrossa space. The side edge portion of the FPC 32 may be attached to theframe 16 with an adhesive (adhesive tape) 42.

The first side surfaces 34 c of the LEDs 34 are substantially flush withthe second main surface S2 of the light guide LG The fixing tape TP2 isattached over the first side surfaces 34 c and the second main surfaceS2 of the light guide LG The LEDs 34 are fixed to the light guide LGwith the fixing tape TP2 and are supported on predetermined positions.The fixing tape TP2 comprises a strip-shaped base 42 a formed of, forexample, polyethylene terephthalate (PET) or the like and a strip-shapedadhesive sheet 42 b overlaid on the base 42 a. For example, a thermallyreactive adhesive sheet formed of polyurethane or the like is used asthe adhesive sheet 42 b. When heated to about 70° C. to 120° C., theadhesive sheet 42 b produces an adhesion force by reaction with theattached objects. The thermally reactive adhesive sheet 42 b can producean adhesion force which is about 3 to 5 times the adhesion force of ageneral double-faced adhesive tape. The adhesive sheet 42 b may betransparent or the adhesive sheet 42 b may be black with black ink,etc., and have a light-shielding function.

The fixing tape TP2 is provided from the LEDs 34 to the light guide LGand is intended for fixing them in a state where they abut each other,and the fixing tape TP2 is not attached to the bottom plate 17.

The fixing tape TP2 has a width W2 which is greater than the width ofthe LEDs 34 and has a length L (see FIG. 5 ) which is substantially thesame as the length of the short sides of the light guide LG The fixingtape TP2 is arranged along a short side of the light guide LQ andsubstantially half of the area of the adhesive sheet 42 b in a widthdirection is attached to the first side surfaces 34 c of the LEDs 34.The remaining area of the adhesive sheet 42 b is attached to the secondmain surface S2 of the light guide LG.

As described above, since the adhesive sheet 42 b produces a strongadhesion force, even if the adhesive sheet 42 b is attached to arelatively small attachment area, the adhesive sheet 42 b can still befirmly attached to the area. Therefore, the LEDs 34 can be firmly fixedto the light guide LG and can be stably supported on predeterminedpositions by the fixing tape TP2. The above-described thermally reactiveadhesive sheet may be used as an adhesive which attaches thepreviously-described FPC 32 to the short side plate 16 d.

As shown in FIGS. 2 and 3 , the backlight unit 20 comprises aframe-shaped double-faced adhesive tape TP1. The double-faced adhesivetape TP1 is attached to the frame 16.

As shown in FIG. 4 , in a light source side end portion of the case 23,the double-faced adhesive tape TP1 is attached to the FPC 32 via aspacer SP1 and is further attached to the light-shielding tape 45.

The backlight unit 20 constituted as described above is attached to theliquid crystal panel 12 with the double-faced adhesive tape TP1. Aninner peripheral portion of the double-faced adhesive tape TP1 isattached to the polarizer PL1, and an outer peripheral portion of thedouble-faced adhesive tape TP1 is attached to the first substrate SUB1via a spacer SP2. The outer peripheral edges of the backlight unit 20match the outer peripheral edges of the first substrate SUB1.

The FPC 32 of the light source unit 30 is connected to the FPC 22 viathe connecting terminal 32 c (see FIGS. 1 and 2 ). When a drive currentis supplied to the LEDs 34 via the FPC 22 and the FPC 32, the LEDs 34are lit up. The light emitted from the LEDs 34 enters the light guide LGfrom the incidence surface EF, propagates through the light guide LG oris reflected off the reflective sheet RE, and is emitted from the firstmain surface (emission surface) S1 to the liquid crystal panel 12 side.

According to the backlight unit 20 and the liquid crystal display device10 of the present embodiment constituted as described above, the LEDs 34of the light source unit 30 are firmly fixed to the light guide LG andare supported on predetermined positions by the fixing tape TP2.Therefore, the FPC (wiring board) 32 of the light source unit 30 doesnot have to have the function of supporting and fixing the light sourceunit 30, and the width W1 of the FPC 32 can be considerably reduced.When the width W1 of the FPC 32 is reduced, the distance between theshort side plate 16 d of the case 23 and the incidence surface EF of thelight guide LG can be reduced. As a result, the frame width on the lightsource side of the backlight unit 20 and the frame width on the lightsource side of the liquid crystal display device 10 can be reduced, andthe frame can be narrowed, accordingly.

The FPC 32 does not overlap the light guide LG and is separated from theincidence surface EF. Therefore, the thickness of the backlight unit 20can be reduced.

Further, when viewed from the incidence surface EP side, the side edge32 a of the FPC 32 is drawn back from the light-emitting surfaces 34 aof the LEDs 34, and therefore the light from the light-emitting surfaces34 a of the LEDs 34 may leak upward. Regarding this, in the presentembodiment, the first optical sheet (diffusing sheet) OS1 has the lightsource side end portion OSE, and the light source side end portion OSEextends from the light guide LG beyond the incidence surface EF andcovers the incidence surface EF and the light-emitting surfaces 34 a ofthe LEDs 34. The black print BP and the light-shielding tape 45 areprovided on the light source side end portion OSE, and a light-shieldingfunction is thereby given to the light source side end portion OSE.Therefore, the gap between the FPC 32 and the incidence surface EF canbe light-shielded by the light source side end portion OSE of the firstoptical sheet OS1, and light leakage from the LEDs 34 can be prevented,accordingly.

As described above, in a conventional structure, a wiring board (FPC) ofa light source unit not only has the function of fixing and electricallyconnecting LEDs but also has the function of blocking light from LEDsand the function of fixing LEDs in the state of abutting a light guide.On the other hand, in the present embodiment, the function of the FPC 32is limited to the function of supplying current to the LEDs 34, and thelight-shielding function is given to the optical sheet OS1 and thefixing function is given to the fixing tape TP2. More specifically, thelight-shielding function is given to the optical sheet OS1 by projectingthe optical sheet OS1 from the light guide LG and forming alight-shielding area. Further, the fixing function is given to thefixing tape TP2 alone by providing the fixing tape TP2 on the oppositeside of the LEDs 34 to the FPC 32 and using an highly-adhesive adhesivesheet as the light-shielding tape TP2. As a result, the size of the FPC32 can be considerably reduced, and the frame on the light source sideof the liquid crystal display panel can be narrowed.

As described above, according to the present embodiment, a backlightdevice and a liquid crystal display device which can achieve narrowingof a frame and reduction of a thickness can be obtained.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel embodiments described hereinmay be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the embodimentsdescribed herein may be made without departing from the spirit of theinventions. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the inventions.

All structures which can be implemented by a person of ordinary skill inthe art through arbitrary design changes based on the structuresdescribed above as the embodiment of the present invention come withinthe scope of the present invention as long as they encompass the spiritof the present invention. For example, the outer shape and inner shapeof each of the liquid crystal panel, components of the backlight unitand the case are not limited to a rectangle, but one or both of theouter shape and inner shape may be a polygon, a circle, an ellipse orother shape such as a combination thereof in a plan view. The liquidcrystal display device and the backlight device are not necessarily flatbut may be partially or entirely curved or inclined. The materials ofcomponents are not limited to those described above but can be selectedfrom various other materials.

Regarding advantages other than those described in the embodiment,advantages obvious from the description and advantages appropriatelyconceivable by a person of ordinary skill in the art are regarded asadvantages achievable from the present invention as a matter of course.

What is claimed is:
 1. A backlight device comprising: a case having abottom plate; a light guide having a front surface as an emissionsurface, a rear surface opposed to the front surface, and an incidencesurface that is one of side surfaces of the light guide, the rearsurface facing to the bottom plate; a plurality of light-emittingelements facing the incident surface of the light guide, each of thelight-emitting elements having a bottom surface and a light-emittingsurface facing the incidence surface of the light guide; a fixing tapearranged on the bottom plate, each of the bottom surfaces of thelight-emitting elements and the rear surface of the light guide beingadhered to the fixing tape; and a light-shield facing the fixing tapethrough the light guide.
 2. The backlight device of claim 1, wherein thefixing tape is attached to entire areas of the bottom surface of each ofthe light-emitting elements and an edge portion of the rear surfaceclose to the incidence surface of the light guide.
 3. The backlightdevice of claim 1, further comprising an optical sheet on the frontsurface of the light guide, wherein the optical sheet has a light sourceside end portion extending toward the light-emitting elements andoverlapping the light-emitting elements.
 4. The backlight device ofclaim 3, wherein the light shield is formed on the light source side endportion.
 5. The backlight device of claim 1, further comprising: awiring board with a wiring line, the plurality of light-emittingelements being mounted on the wiring board.
 6. The backlight device ofclaim 5, wherein the wiring board faces the bottom plate through thelight-emitting elements, the wiring board has a side edge located abovethe light-emitting elements, and a part of each of the light-emittingelements is overlapping the wiring board, and the light-emitting surfaceof each light-emitting element is located at a position projecting fromthe side edge toward the light guide.
 7. The backlight device of claim6, wherein the case includes a side plate which stands along a side edgeof the bottom plate and faces the light-emitting elements with a gap,and a part of the wiring board is attached to the side plate with anadhesive.
 8. The backlight device of claim 1, wherein the light-shieldis located above the incidence surface of the of the light guide and thelight-emitting surface of each of the light-emitting elements.
 9. Thebacklight device of claim 1, wherein the fixing tape has alight-shielding property.
 10. A liquid crystal display devicecomprising: a liquid crystal panel; and the backlight device of claim 1which faces the liquid crystal panel.
 11. A backlight device comprising:a case having a bottom plate; a light guide having a front surface as anemission surface, a rear surface opposed to the front surface, and anincidence surface that is one of side surfaces of the light guide, therear surface facing on the bottom plate; a plurality of light-emittingelements facing the incident surface of the light guide, each of thelight-emitting elements having a bottom surface and a light-emittingsurface facing the incidence surface of the light guide; a fixing tapearranged on the bottom plate, each of the bottom surfaces of thelight-emitting elements and the rear surface of the light guide beingadhered to the fixing tape; and a light-shield facing the fixing tapethrough each of the light emitting elements.
 12. The backlight device ofclaim 11, wherein the fixing tape is attached to entire areas of thebottom surface of each of the light-emitting elements and an edgeportion of the rear surface close to the incidence surface of the lightguide.
 13. The backlight device of claim 11, further comprising anoptical sheet on the front surface of the light guide, wherein theoptical sheet has a light source side end portion extending toward thelight-emitting elements and overlapping the light-emitting elements. 14.The backlight device of claim 11, further comprising: a wiring boardwith a wiring line, the plurality of light-emitting elements beingmounted on the wiring board.
 15. The backlight device of claim 14,wherein the wiring board faces the bottom plate through thelight-emitting elements, the wiring board has a side edge located abovethe light-emitting elements, and a part of each of the light-emittingelements is overlapping the wiring board, and the light-emitting surfaceof each light-emitting element is located at a position projecting fromthe side edge toward the light guide.
 16. The backlight device of claim15, wherein the case includes a side plate which stands along a sideedge of the bottom plate and faces the light-emitting elements with agap, and a part of the wiring board is attached to the side plate withan adhesive.
 17. The backlight device of claim 11, wherein the fixingtape has a light-shielding property.
 18. A liquid crystal display devicecomprising: a liquid crystal panel; and the backlight device of claim 11which faces the liquid crystal panel.